Selective sulfur dioxide adsorbents prepared from designed dispersions of groups IA and IIA metal oxides on alumina

Supported M(I)/alumina and M(II)/alumina adsorbents were prepared using M(n+)(acac)(n) as the precursor. These materials may be decomposed by careful heating to create dispersions of M(n+)O(n/2)/alumina which are SO2 adsorbents, These adsorbents have been characterized by elemental analyses, diffuse reflectance infrared Fourier transform analysis spectroscopy, SO2 adsorption capacity, and powder X-ray diffraction. The MgO/alumina prepared from Mg(acac)(2) . 2H(2)O shows high dispersion of Mg species which are stable against sintering even when calcined to 500 degrees C. The incremental SO2 sorption capacity of this material shows nearly 1 mol SO2/mol Mg2+ in the sample, The sample prepared from Li(acac) shows more SO2 adsorption than the MgO/alumina for loadings <150 mu mol/g alumina. However, the LiO/alumina samples show low incremental adsorption of SO2 per mol of Li ion (0.12 mol/mol) at metal loadings greater than 150 mu mol/g alumina. These results are discussed in the framework of ensemble theory in the light of the solution chemistry of the metal acetylacetonates. (C) 1996 Academic Press, Inc.